Momona Ethiopian Journal of Science最新文献_第3页

Periodic Point as a Recurrent Formation Using the Logistic Function: A Survey 使用Logistic函数作为递归形式的周期点：综述

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-12-26 DOI: 10.4314/mejs.v14i2.5

Patrick Akwasi Anamuah Mensah, W. Obeng-Denteh, Kwasi Baah Gyamfi

{"title":"Periodic Point as a Recurrent Formation Using the Logistic Function: A Survey","authors":"Patrick Akwasi Anamuah Mensah, W. Obeng-Denteh, Kwasi Baah Gyamfi","doi":"10.4314/mejs.v14i2.5","DOIUrl":"https://doi.org/10.4314/mejs.v14i2.5","url":null,"abstract":"In topological dynamical systems (TDS), recurrence (periodic–like recurrence) is one of the important concepts in its studies but one major problem is the inability to demonstrate and/or illustrate its formation in the orbit structure of system from a topological point of view. In this paper, the logistic function was applied to demonstrate the periodic point as a recurrent formation (periodic–like recurrence) in the topological dynamical system and dynamical system. The Wolfram Alpha computational knowledge engine was used in obtaining the tables and the figures for the study through various examples of the logistic function. The study shows that period – 2 recurrence is formed when the trajectory of the function is made up of two different values that keep repeating after successive iterations as a result of the period – 2 orbits when the parameter of the function is between 3 and 3.45. The study again shows that when the parameter of the function is greater than 3.83 there is a period – 3 point hence the formation of other periodic points. Convincingly, beyond this period – 3 is another subsequent period called the period-doubling cascade leading into chaos. This period-doubling asserts that other periodic–like recurrences are also present, hence period –n recurrent exists. \u0000 ","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44380420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gender Differentia Among Fish Farmers Within Ilorin Metropolis, Kwara State, Nigeria 尼日利亚夸拉州伊洛林大都会内养鱼户的性别差异

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-12-26 DOI: 10.4314/mejs.v14i2.2

Ayeloja A. A, Jimoh W. A, Adebisi G. L, A. M. A

{"title":"Gender Differentia Among Fish Farmers Within Ilorin Metropolis, Kwara State, Nigeria","authors":"Ayeloja A. A, Jimoh W. A, Adebisi G. L, A. M. A","doi":"10.4314/mejs.v14i2.2","DOIUrl":"https://doi.org/10.4314/mejs.v14i2.2","url":null,"abstract":"Gender differentia among fish farmers within the Ilorin metropolis, Kwara State, Nigeria was studied with the aim of evaluating the level of involvement of the different gender in fish production activities, accessing their access to credit, and the constraints faced by them. A multistage sampling technique using a structured questionnaire was adopted for this study, the sample size was 210 using a structured questionnaire. Data were analyzed using SPSS 16.0. 61.90% of respondents were male while 52.5% and 49.2% of female and male respondents respectively were in their active age group of < 30 years. Females were more involved in fish marketing (42.90%) and fish processing (48.75%). There exist a significant association (p<0.05) between gender and level of involvement in fish marketing (χ2=9.20, p<0.05), access to land (χ2=10.69, p<0.05), and fish production activities (χ2=11.83, p<0.05). Access to credit was poor. Constraints faced include poor access to credit facilities, inadequate information, high cost of feed production, and poor water quality. It is therefore recommended that access to credit facilities banks of agriculture, microfinance banks, and commercial banks should be improved on while fish farmers are also encouraged to form cooperative societies as it will improve the capacity building of farmers and ease their credit acquisition for farming activities.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48856710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Measurement of Radionuclides Concentration and Radiological Health Assessment of Some Selected Table Waters in Ilorin 伊洛林部分地表水放射性核素浓度测定及辐射卫生评价

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-10-22 DOI: 10.4314/mejs.v14i1.5

Orosun M M, Fabowale P A, Akinyose F C, Oluyide S O, Mark U, Olaniyan T A, Oduh V O

{"title":"Measurement of Radionuclides Concentration and Radiological Health Assessment of Some Selected Table Waters in Ilorin","authors":"Orosun M M, Fabowale P A, Akinyose F C, Oluyide S O, Mark U, Olaniyan T A, Oduh V O","doi":"10.4314/mejs.v14i1.5","DOIUrl":"https://doi.org/10.4314/mejs.v14i1.5","url":null,"abstract":"In order to ensure radiation monitoring and protection, an investigation and assessment of radiological risks that may be associated with the consumption of table waters commonly consumed in Ilorin, Nigeria, was carried out. The activity concentration level of 238U, 232Th, and 40K was determined using thallium activated 3˝×3˝ [NaI(TI)] detector connected to ORTEC 456 amplifier. The radiological risks due to the consumption of the samples were then estimated. The highest annual effective dose (AED) values were obtained from VW and the minimum was obtained from UW water. The AED decreases in the order VW>HW>IW>MW>DW>UW. This implies that VW water constitutes more radiation exposure followed by HW, IW, MW, DW, and then UW Water. The values estimated for MW, DW, and UW water were all lower than the world average value of 1 mSv/y and hence pose no serious radiation hazard. While the values estimated for VW, IW, and HW waters were slightly higher than the recommended threshold value, suggesting a possible risk of radiation exposure to customers. The Excess Lifetime Cancer Risks corroborated the findings of the AED, implying that the probability of developing cancer is high for most of the water samples. Since the values of the estimated hazard parameters were mostly higher than the recommended limits for all age groups, it is recommended that public water system should be monitored and efforts should be made to educate and enlighten the public on radiation exposure, its health effects, and remedial actions necessary to reduce radionuclides concentration in drinking water.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43818911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Coating Properties of Alkyd Resin, Epoxy Resins and Polyurethane Based Nanocomposites: A Review 醇酸树脂、环氧树脂和聚氨酯基纳米复合材料的涂层性能综述

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-10-22 DOI: 10.4314/mejs.v14i1.1

Ikhazuagbe H Ifijen, Nyaknno U Udokpoh, Gregory E Onaiwu, Eribe M Jonathan, Esther U Ikhuoria

{"title":"Coating Properties of Alkyd Resin, Epoxy Resins and Polyurethane Based Nanocomposites: A Review","authors":"Ikhazuagbe H Ifijen, Nyaknno U Udokpoh, Gregory E Onaiwu, Eribe M Jonathan, Esther U Ikhuoria","doi":"10.4314/mejs.v14i1.1","DOIUrl":"https://doi.org/10.4314/mejs.v14i1.1","url":null,"abstract":"The uniqueness of alkyd resin, epoxy resin, and polyurethane nanocomposites has brought prominent recognition to the field of heavy-duty coating materials. This is expected due to the collaborative features of nano-sized materials such as the high surface area to volume ratio, great functionality per-unit space, extremely small sizes with high density, and that of alkyd resin, epoxy resin, and polyurethane (biodegradability, great gloss retention, adaptability, flexibility, durability, good drying properties, and weathering resistance). The objective of this review was to analyze the extent and currency of research and the development of alkyd, epoxy, and polyurethane nanocomposites in coating applications. Some of the several types of modifications discussed in this review are the incorporation of varying types of nanoclay and metal nanoparticles materials into alkyd resins, the incorporation of carbon nanotubes, MGel-graphene oxide (GO)/gelatin (MGel), Ni (II) Complex-Zeolite and starch-modified nano-ZnO into epoxy resin and the incorporation of (Rb2Co(H2P2O7)2.2H2O), modified nanoparticles of ZnO, diminished graphene oxide (dGO) into polyurethane and their effects on coating applications. The various studied modifications resulted in nanocomposite end-products with much improved properties. However, there are several challenges to the development of nanocomposites that need urgent attention. Some of the challenges discussed are the difficulty involved in transforming fabricated nanocomposites from laboratory to commercialized scale, the capital-intensive nature of synthesizing large nanopowder, etc.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44150229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigations on Tribological Performance of Sisal Fiber Reinforced Polypropylene Composites 剑麻纤维增强聚丙烯复合材料摩擦学性能研究

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-10-22 DOI: 10.4314/mejs.v14i1.3

Temesgen Berhanu Yallew, Mulubrhan Mokonen, Tsegay Tesfay

{"title":"Investigations on Tribological Performance of Sisal Fiber Reinforced Polypropylene Composites","authors":"Temesgen Berhanu Yallew, Mulubrhan Mokonen, Tsegay Tesfay","doi":"10.4314/mejs.v14i1.3","DOIUrl":"https://doi.org/10.4314/mejs.v14i1.3","url":null,"abstract":"There has been an increase in global interest in the development of natural fiber-reinforced composites. Natural fibers extracted from plants are receiving more attention from researchers, scientists, and academics due to their use in polymer composites and their environmentally friendly nature and sustainability. Recently, sisal fiber-reinforced polymer composites have been used in a variety of engineering applications like aerospace, automotive, marine, and other mechanical components, where tribological properties are of prime consideration. In this endeavor, experiments have been conducted to determine the tribological behavior of sisal fiber-reinforced polypropylene composite. Pin-on-disc wear tests have been conducted on specimens at various combinations of sliding velocities (1-3 m/s), sliding distances (1000-3000 m), and applying normal loads (10-30N). Using Response Surface Method (RSM), a mathematical model has been developed to predict the friction and wear loss behavior of the sisal fiber-reinforced polypropylene (PP) composites. To ensure the validity of the developed model, the Analysis of variance (ANOVA) technique has been applied. Important process parameters and material variables that exert significant influence on sliding wear loss have been determined with the help of systematic experimentation. Scanning Electron Microscope (SEM) has been used to probe morphological observation of the worn surface. Results revealed that the highest volumetric wear loss has been recorded at the highest values of applied load and this has been supported by the morphological study demonstrated by the scratches, as well as wider and deeper plowing marks on the worn surfaces.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48498942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pumped Hydro- Energy Storage System in Ethiopia: Challenges and Opportunities 埃塞俄比亚抽水蓄能系统:挑战与机遇

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-10-22 DOI: 10.4314/mejs.v14i1.2

Dawit Abay Tesfamariam, Asfafaw T Hailesialssie, Muyiwa S. Adaramola

引用次数: 0

Age and growth of gilthead sea bream (Sparus aurata Linnaeus, 1758) from Northern Aegean Sea (Turkey) 北爱琴海(土耳其)金头鲷(Sparus aurata Linnaeus, 1758)的年龄和生长

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-10-22 DOI: 10.4314/mejs.v14i1.6

Ö. Cengiz

引用次数: 0

Improved Receiver Design Concepts for Parabolic Dish Direct Solar Cooking Systems 改进的抛物面碟直接太阳能烹饪系统接收器设计概念

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-10-22 DOI: 10.4314/mejs.v14i1.4

Austin P Theu, Cuthbert Z M Kimambo

{"title":"Improved Receiver Design Concepts for Parabolic Dish Direct Solar Cooking Systems","authors":"Austin P Theu, Cuthbert Z M Kimambo","doi":"10.4314/mejs.v14i1.4","DOIUrl":"https://doi.org/10.4314/mejs.v14i1.4","url":null,"abstract":"In developing countries, solar cooking technology is considered one of the key measures in dealing with deforestation and environmental pollution. However, their adoption and utilization have been insignificant due to social, cultural, and technical challenges, among others. For parabolic dish direct solar cookers, one of the critical and most important components of the system is a receiver since its performance greatly affects the entire system. This paper presents part of the findings of the study which investigated the prospects of improving the technical performance of parabolic dish direct solar cooking systems by focusing on the identification of prospective heat loss reduction mechanisms on the receiver. The study identified the Insulated (IR), Air-filled (AFR), and Oil-filled (OFR) receivers with Base Circular Rings (BCR) as alternatives to the Conventional Receiver (CR) System. Tests were conducted using procedures and protocols given by the American Society for Agricultural Engineers (ASAE). The test results showed that the average power developed by the systems was 185 W for the IRBCR system, 90 W for the OFRBCR system, 92 W for the AFRBCR system, and 118 W for the CR system. The standardized cooking power for a temperature difference of 50oC, PS (50), was 291 W for the IRBCR system, 11 W for the OFRBCR system, 272 W for the AFRBCR system, and 142 W for the CR system. The results further revealed that the overall efficiencies were 23% for the IRBCR system, 9% for the OFRBCR system, 12% for the AFRBCR system, and 18% for the CR system. The receiver efficiencies were found to be 27% for a system with IR, 11% for a system with OFR, 14% for a system with AFR, and 21% for a system with CR. The study concluded that the performance improved when the system with the IR was used while the magnitudes of the performance parameters of the AFR and OFR were lower than the CR system.","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":"75 1","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70566979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Challenges and Opportunities of Backyard Poultry Production in Ezha District, Gurage Zone of Ethiopia 埃塞俄比亚古拉格区埃扎区后院家禽生产的挑战与机遇

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-04-11 DOI: 10.4314/mejs.v13i2.7

Mebagebriael Estifanos, Gebrehiwot Tadesse

{"title":"Challenges and Opportunities of Backyard Poultry Production in Ezha District, Gurage Zone of Ethiopia","authors":"Mebagebriael Estifanos, Gebrehiwot Tadesse","doi":"10.4314/mejs.v13i2.7","DOIUrl":"https://doi.org/10.4314/mejs.v13i2.7","url":null,"abstract":"This study was conducted with the objective of assessing the opportunities and challenges of backyard poultry production at three villages in Ezha district, Gurage Zone of southern Ethiopia using a semi-structured questionnaire, field visit and interview with 150 randomly selected respondents. The dominant chicken production system in the study area was an extensive system (74%) with scavenging and seasonal supplementary feeding (53%). Grains are the main feed used. Almost 65% of poultry share the same room with the main house with perch, the rest 20%, and 15%, respectively, use the different shelters. Most of the farmers (80%) use traditional medicine to treat their chicken. The average age of first laying was 5months, mean number of eggs per clutch was 12. The mean clutch size was 3.3 and the hatchability percentage was 72%. The result revealed that the main constraints of village poultry production in the study area, especially in village2 were predator (48%), disease (33.7%), feed shortage (19.3%), market (10%), and the primary opportunity was extension (34%) followed by credit, (24.6%), market (23.4%) and feed access (18%) and, respectively. It is concluded that constraints and opportunities of village chicken production were identified. Controlling predators, improving the management practices, and educating the framers are viable options to improve the livelihood of the households. \u0000 \u0000 ","PeriodicalId":18948,"journal":{"name":"Momona Ethiopian Journal of Science","volume":" ","pages":""},"PeriodicalIF":0.3,"publicationDate":"2022-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48420785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Eighth order Predictor-Corrector Method to Solve Quadratic Riccati Differential Equations 求解二次Riccati微分方程的八阶预测校正法

IF 0.3

Momona Ethiopian Journal of Science Pub Date : 2022-04-11 DOI: 10.4314/mejs.v13i2.2

Wase Kassahun, Alemayehu Shiferaw, S. Gebregiorgis

引用次数: 0